oj.uz

Submission #253077

# Submission time Handle Problem Language Result Execution time Memory
253077 2020-07-26T20:53:00 Z Kubin Tropical Garden (IOI11_garden) C++17
100 / 100
 279 ms 42288 KB 
#include <functional>
#include <cstdint>
#include <cassert>
#include <climits>
#include <vector>
#include <array>

using namespace std;

const size_t nil = SIZE_MAX;

void answer(int);


void count_routes(int _n, int _m, int _t, int E[][2], int _q, int K[])
{
    const size_t n = _n, m = _m, target = _t, q = _q;

    // get edges
    vector<array<size_t, 2>> to(n, {nil, nil});
    for(size_t i = 0; i < m; i++)
    {
        size_t u = E[i][0], v = E[i][1];
        if(to[u][0] == nil)
            to[u][0] = v;
        else if(to[u][1] == nil)
            to[u][1] = v;
        if(to[v][0] == nil)
            to[v][0] = u;
        else if(to[v][1] == nil)
            to[v][1] = u;
    }

    vector<size_t> F(2*n, nil);
    // vertex i+n is vertex after coming through best edge of vertex i
    auto nfix = [&](size_t v, size_t u) {
        return v + (to[v][0] == u ? n : 0);
    };
    for(size_t u = 0; u < n; u++)
    {
        F[u] = nfix(to[u][0], u);
        F[u+n] = nfix(to[u][1] == nil ? to[u][0] : to[u][1], u);
    }

    // rho computation
    vector<bool> vis(2*n), on(2*n);
    vector<size_t> st; st.reserve(2*n);

    vector<size_t> top(2*n, nil);
    vector<int> lambda(2*n), omega(2*n);

    vector<vector<size_t>> G(2*n);

    for(size_t s = 0; s < 2*n; s++)
    {
        G[F[s]].push_back(s);
        // cout << s << " " << F[s] << endl;
        if(vis[s])
            continue;

        assert(st.empty());
        size_t u = s;
        while(true)
        {
            vis[u] = on[u] = true;
            st.push_back(u);

            if(on[F[u]])
            {
                vector<size_t> cycle;
                while(true)
                {
                    auto v = st.back(); st.pop_back();
                    on[v] = false;
                    cycle.push_back(v);
                    if(v == F[u])
                        break;
                }
                for(auto v : cycle)
                    omega[v] = cycle.size(), top[v] = v;
            }
            else if(vis[F[u]])
            {
                lambda[u] = lambda[F[u]] + 1;
                top[u] = top[F[u]];
            }
            else
                { u = F[u]; continue; }
            break;
        }
        while(not st.empty())
        {
            auto v = st.back(); st.pop_back();
            lambda[v] = lambda[F[v]] + 1;
            top[v] = top[F[v]];
            on[v] = false;
        }
    }


    // queries

    vector<pair<vector<int>, int>> tabs(2*n);
    function<pair<vector<int>, int>(size_t)> get_tab = [&](size_t t) -> pair<vector<int>, int> {
        if(not tabs[t].first.empty())
            return tabs[t];
        else if(lambda[t])
        {
            vector<int> cnt;
            function<void(size_t, size_t)> dfs = [&](size_t u, size_t d) {
                while(cnt.size() <= d) cnt.push_back(0);
                cnt[d] += (u < n);
                for(auto v : G[u])
                    dfs(v, d + 1);
            };
            dfs(t, 0);
            return tabs[t] = {cnt, 0};
        }
        else
        {
            size_t u = t;
            vector<int> cnt(omega[t]);
            for(int i = 0; i < omega[t]; i++, u = F[u])
            {
                int sh = (i ? omega[t] - i : 0);
                cnt[sh] += (u < n);
                sh++;
                for(auto v : G[u])
                  if(lambda[v])
                {
                    auto [sub, _] = get_tab(v);
                    (void)_;
                    while(cnt.size() < sh + sub.size()) cnt.push_back(0);
                    for(size_t d = 0; d < sub.size(); d++)
                        cnt[sh + d] += sub[d];
                }
            }
            for(size_t i = omega[t]; i < cnt.size(); i++)
                cnt[i] += cnt[i - omega[t]];
            return tabs[t] = {cnt, omega[t]};
        }
    };

    auto count = [&](int k, size_t t) {
        auto [T, mod] = get_tab(t);
        if(mod)
        {
            int step = mod;
            while(2*step < INT_MAX/5)
                step *= 2;
            while(step > mod)
            {
                while(k >= (int)T.size()+step)
                    k -= step;
                step /= 2;
            }
            while((size_t)k >= T.size())
                k -= mod;
            return T[k];
        }
        else
            return (size_t)k < T.size() ? T[k] : 0;
    };

    for(size_t que = 0; que < q; que++)
    {
        int k = K[que];
        answer(count(k, target) + count(k, target + n));
    }
}

Subtask #1
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 4 ms 640 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 4 ms 640 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 12 ms 5504 KB Output is correct
12 Correct 25 ms 8832 KB Output is correct
13 Correct 48 ms 25012 KB Output is correct
14 Correct 101 ms 30072 KB Output is correct
15 Correct 130 ms 30584 KB Output is correct
16 Correct 96 ms 21496 KB Output is correct
17 Correct 79 ms 17784 KB Output is correct
18 Correct 25 ms 8832 KB Output is correct
19 Correct 103 ms 30072 KB Output is correct
20 Correct 138 ms 30416 KB Output is correct
21 Correct 97 ms 21240 KB Output is correct
22 Correct 81 ms 17816 KB Output is correct
23 Correct 111 ms 33392 KB Output is correct

Subtask #3
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 640 KB Output is correct
2 Correct 1 ms 512 KB Output is correct
3 Correct 1 ms 512 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 256 KB Output is correct
6 Correct 1 ms 768 KB Output is correct
7 Correct 0 ms 384 KB Output is correct
8 Correct 1 ms 512 KB Output is correct
9 Correct 4 ms 640 KB Output is correct
10 Correct 0 ms 384 KB Output is correct
11 Correct 12 ms 5504 KB Output is correct
12 Correct 25 ms 8832 KB Output is correct
13 Correct 48 ms 25012 KB Output is correct
14 Correct 101 ms 30072 KB Output is correct
15 Correct 130 ms 30584 KB Output is correct
16 Correct 96 ms 21496 KB Output is correct
17 Correct 79 ms 17784 KB Output is correct
18 Correct 25 ms 8832 KB Output is correct
19 Correct 103 ms 30072 KB Output is correct
20 Correct 138 ms 30416 KB Output is correct
21 Correct 97 ms 21240 KB Output is correct
22 Correct 81 ms 17816 KB Output is correct
23 Correct 111 ms 33392 KB Output is correct
24 Correct 1 ms 384 KB Output is correct
25 Correct 14 ms 5504 KB Output is correct
26 Correct 26 ms 8832 KB Output is correct
27 Correct 245 ms 25012 KB Output is correct
28 Correct 110 ms 30072 KB Output is correct
29 Correct 142 ms 32248 KB Output is correct
30 Correct 108 ms 23292 KB Output is correct
31 Correct 91 ms 19448 KB Output is correct
32 Correct 28 ms 9464 KB Output is correct
33 Correct 133 ms 31736 KB Output is correct
34 Correct 143 ms 32376 KB Output is correct
35 Correct 106 ms 22648 KB Output is correct
36 Correct 86 ms 19448 KB Output is correct
37 Correct 111 ms 35184 KB Output is correct
38 Correct 279 ms 42288 KB Output is correct